class School:
    def __init__(self,Department):
        self.Department = Department

class Department:
    def __init__(self,Instructor,student):
        self.Instructor = Instructor
        self.student = student

class Instructor:
    def __init__(self,Name,Department,subject):
        self.Name = Name
        self.Department = Department
        self.subject = subject

class student:
    def __init__(self,Name,Department,subject):
        self.Name = Name
        self.Department = Department
        self.subject = subject